<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    'use strict'

    const target = {
      foo: 'xxx',
      bar: 'yyy'
    }

    const proxy = new Proxy(target, {
      get (target, key, receiver) {
        return Reflect.get(target, key, receiver)
      },
      set (target, key, value, receiver) {
        return Reflect.set(target, key, value, receiver)
      },
      deleteProperty (target, key) {
        return Reflect.deleteProperty(target, key)
      }
    });

    proxy.foo = 'zzz'
    console.log(proxy)
  </script>
</body>
</html>  